| 摘要 |
PURPOSE:To obtain a catalyst for producing methacrylic acid having a high reaction activity and selectivity together with a long catalytic life. CONSTITUTION:A catalyst for producing methacrylic acid composed of a partially neutralized salt of heteropolyacid represented by general formula PaMobVcAsdXeYfOg (wherein P, Mo, V, As and O are respectively phosphorus, molybdenum, vanadium, arsenic and oxygen, X is at least one kind of an element selected from a group consisting of potassium, rubidium, cesium and thallium and Y is at least one kind of an element selected from a group consisting of copper, silver, bismuth, iron, cobalt, antimony, lanthanum and cerium) and not substantially containing an ammonium radical and a nitrate radical is produced by a method wherein an ammonium radical and a nitrate radical are allowed to be present in an aqueous soln. or suspension of all of catalyst raw materials so as to adjust the pH of said soln. or suspension to 3-9 and the solid obtained by concentrating and drying this soln. or suspension is baked at 400-500 deg.C in an inert gas atmosphere. |
